# ceng = 1
#
# while ceng<=5:
#     count = 1
#     while count <= ceng:
#         print("*",end='')
#         count+=1
#     ceng+=1
#     print()

# ceng = 5
# while ceng>=1:
#     count = 1
#     while count <=ceng:
#         print("*",end='')
#         count+=1
#     ceng-=1
#     print()
# flag = True
# sum1 = 0
# for i in range(1,100,2):
#     if flag:
#         sum1 += i
#         flag = False
#     else:
#         sum1 -= i
#         flag = True
# print(sum1)

# s = 'abc'
#
# s1 = '_'.join(s)
# print(s1)
# if None:
#     print('Hello')
# r = range (10)
# print (r)
print(dir(list))
